Treatment of textile elements or yarn derived from rayon filaments or fibers



July 8, 1930. I w STERNBERG 1,770,047

TREATMENT OF TEXTILE ELEMENTS OR YARN DERIVED FROM RAYON FILAMENTS OR FIBERS Filed Aug. 27, 1926 Patented July 1930 UNITEDtSTATE'S PATENT OFFICE woL EmAn M. s'rnmmmw, or New YORK MILLS, imwvonx, assienon ro 1101mm a. CAMPBELL, or names, new YORK TREATMENT OF TEXTILE ELEMENTS 0R. YARN DERIVED FROM RAYON FILAMENTS 03 Application filed August 27, 1926. Serial No. 131,966.

This invention relates, primarily, to the treatment of textile elements or yarn derived from rayon filaments or fibers; it has especial reference to a method of lusterizing such elements; and it involves a step of stretching the same to a predetermined degree.

It has heretofore been proposed to produce rayon yarn by cutting commercial rayon filaments or fibers to relatively short lengths and then spinning a plurality of these out sections together to produce a type of textile element or yarn having certain characteristics not possessed by the filaments, themselves, before they are spun together.

The procedure involved in developing this new yarn has a tendency to remove some of the surface luster of the yarn. In other words, the spinning-which involves a twisting (if the short-length filamentsseems to have the effect mentioned: That is to say, it is known that when rayon fibers or filaments are twisted together, as by spinning, the luster of the resulting spun yarn is always less than that of the or1ginal fibers when they are laid, parallel. This loss of luster may be attributed to the fact that ontwisting a parallel bunch of fibers or filaments, the latter assume anarrangement in space which is infiuenced by the inherent rigidity of the component fibers. ,Each fiber will form a sort of spiral; but these spirals, except only in.

some instances, furnish no stretches or sections which are parallel .to each other. It has been discovered that by partially twisting such spun yarns, the tendency of the fibers thereof is to assume a parallel arrangement for greater lengths, with a resulting improvement'of luster. This effect is particularly noticeable when the backetwisting is done with the fibers in the moist state. Such treatment may result in loss of tensile strength of the yarn--due, doubtless, to a decrease in points of contact of the fibers-which causes a break when the yarn is placed under tension, this break being, to a great extent, a

slippage of fibers, one past the other.

A similar lusterizing-as effected by backtwisting the yarnm ay be produced by stretching it, such action a parently tending to restore the component fi rs in parallelism over increased stretches or sections 'of the spirals. Artificial fibers and rayon filaments possess great rigidity and resilience. T0 attain the maximum lusterizing efi'ect, this rigidity must, to a'great extent, be overcome,

and this can be eifectually accomplished by stretching the spun yarn or elements while in a moist state. If such stretched elements be left to dry, then and while under tension, the resulting yarn does have an improved luster and, at the same time, due to improved contact between the fibers, the yarn is very appreciably improved in strength, its inhave preferably been rather high, approa'ching as closely as is safe the breaking loads of the wet yarns. Inasmuch as no yarns are entirely uniform throughout their length, the tensions selected have usually been somewhere between one-half (v and two-thirds of the average breaking loads of the wet yarns. It being easier, in practice, to measure a load (tension) applied by the ef,

feet it produces upon the stretched (tensioned) yarn, it is my preferred practice to stretch the wet yarn close to ten per cent (10%),.and then to permit it to dry while maintaining the stretch unaltered.

In the accompanying drawing, which is more or less diagrammatic, I have illustrated, in two comparative views, the relative position of the fibers or filaments before and after stretching, that is, tensioninfi In other words, in Fig. 1, the fibers or la shown in the position they assume during the ments are spinning operation, such filaments being designated by the reference-character 3; while, Y

. different stages of manufacture For instance, if the yarn is to be bleached or dyed, or w ll; have in any way to pass through a wet state finishing operations are made on yarn in the a drier and dried.

during finishing operations, the obvious place for stretching will be during the subse uent drying. It may be done in skeins (i the form of skeins; or in continuous strands, by carrying the yarn out of the last wash-water on a system of rollers possessing graded speeds, this operation imparting a stretch to the wet yarn and maintaining it in that condition until the yarn has been passed through processes of knitting or weaving.

' What I claim is:

1. The method of lusterizing a spun rayonelement which consists in appreciably ten-- I sioning the same, and efi'ecting a rearrangement of'the filaments tion;

2. The method of lusterizing a spun rayon element which consists in appreciably tensioning the same while in a moist condition, and eifectin a rearrangement of the filaments toward a parallel relation. 4

3. The method of lusterizing a spun rayon toward a parallel rela element which consists in appreciably ten- ,sioning the same while in a moist condition,

then drying the tensioned element, and-efiecting a rearrangement of the filaments toward a parallel relation. g

4. The method of lusterizing yarn resulting from cutting rayon filaments into relatively short lengths and, then, spinning the sameinto a textile element or yarn, which consists in tensioning said element and maintaining it tensioned until substantially dry.

In testimony whereof I afiix my signature.

WOLDEMAR M. STERNBERG. 

